guys im losing water but if i dont boot it and drive normally it dont go down. Any ideas what this might be?

thanks in advance

 

Year/model would help

Tony

 

hi mate sorry its a 1998 sti import.
thanks

 

Classics are a bit reknown for having the plastic bit at the top of the radiator go brittle and crack, so you can lose water that way, other options are the top on the expansion tank (also common) HG failure or split pipe.
When the car is running, are all the pipes in the cooling system solid or are they squishy?

Tony

 

think they r squishy mate they are not solid do you mean after a run or just with the engine idling from cold or dont that matter. sorry if i sound thick but im new to scoobs.

 

when the car is idling does the bottom radiator hose get hot? either whilst idling or switched off, are the top and bottom hose soft and squishy or is one of them rock hard? Is there any noticeable signs of water lose around any of the rads pipes or the rad it self? if you let the car idle look underneath for any sign of any slight water lose. How long have you owned the car and have you been driving it hard?

 

Squishy means that there is air in the system the worry is how the air got there in the first place.
Has the car had a recent coolant change? or can you say when you first noticed the issue (ie after a long run out on a hot day etc)

Tony

 

so it dosent lose water if driven off boost, but as soon as you drive it hard you lose water. Sounds as if its a slight crack in the hg and when on boost its pushing water out. Have you ckecked your oil. if using the dipstick has it got small water globules, or you could drop the oil for a better inspection....

 

i had exactly the same with my classic and it was the plastic ends on the rad.

 

hi guys thanks for all ur replies there is no visible sign of water on the dipstick how can i get this checked someone suggested pressure test any ideas?

 

No it doesn't, it just means the system hasn't built up any pressure, I.e you have a leak somewhere or you haven't let it warm up enough.

He could buy a cooling system pressure test kit at circa £150 or get down a garage and get them to test it for a few quid. (diagnosis only)

You need to fill the cooling system back up, (water will do) and then pressurise the cooling system with a pump attached to the top of the expansion tank. You'll soon find the leak.

If you can't find the leak, leave the pressure kit attached and remove the spark plugs. Crank engine and watch for any water exiting the plug holes, if it does.. Headgaskets!
You also should be checking the rad cap can hold the pressure that is stamped on the cap..

 

bttt

 

had similar issues on my classic .water kept dissapearing no water in oil etc .couldnt find a drip anywhere then one day i went down the road and a puddle of water underneath my rad had blown down the plastic on it

 

hi ozzy what you mean the plastic edges on the rad thanks

 

on my radiator the sides (left and right) were hard black plastic and it just cracked